[davix] Be helpful and state file name in open error.
[davix] Be helpful and state file name in open error.

root-mirror/root,root-mirror/root,olifre/root,olifre/root,karies/root,olifre/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,karies/root,root-mirror/root,root-mirror/root,olifre/root,karies/root,karies/root,karies/root,olifre/root,olifre/root,root-mirror/root,karies/root,karies/root,karies/root,root-mirror/root,olifre/root,karies/root,olifre/root